Automatic draft regulator



AUTOMATIC DRAFT REGULATOR. APPLICATION FILED SEPT. 24, 1919. 15,42%931 l n Patented July M9 1922.,

I f TQITT j WWTT E I I ha n I .l A@ I@ @I :0 I 0. g w l 'l NQ v@ 'I Tw: E@ TQS. I@ 5h' :f @I@@@@ v INVENTOR @wmfyle fS/zermvd C. I. SHERWOO.

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CARLYLE 3'. SHERWOOD, 0F SAN FRANCISCO, CALIFORNIA, ASSIGNOR T0 SGEN C0., 0F

SAN FRANCISCO, CALIFORNIA, A CORPORATION OF CLIEORNA.

AUTOMATIC DRAFT REGULATR.

Specication of Letters Patent.

Patented duly 1l,

.application :Bled September 221919. Seria-l Elo. 326,105.

T 0 all 'wko-m' z'l may concern.'

Be it known that l', Csnnrns d. SHnRwooD, acitizen of the United States, residing at the city and county of San Francisco and State of California, have invented new .and useful improvements in Automatic Eraft Regulators, of which the following is a; specification.

This invention relates to a draft regulator for hoilers and the like and especially to means for automatically varying ,the air lorv through the furnace as the fires are increased or decreased.' i

ln actual practice, ifthe steam pressure in a boiler changes under variations in load, it is customary to change the oil pressure to the oil burners and thereby the size ofthe res under the boiler, such change in the lire increasing or decreasing the temperature and consequently the volume of steam generated.. In order tov burn this changed amount of fuel economically it is necessary to change the rate ofair iovv through the furnace; for instance, by changing the damper opening to the stack or the position of the air regulator at the front of the furnace; or if. forced or induced draft is employed to change the speed of the fan or the volume of steam passed through the jet.

One of the objects of the present invention is to provide a simple, substantial and easily installed mechanism whereby either the stack damper or the furnace front regu-4 lator, or both, may be automatically operated to vary the air owthrough the furnace. Further, to provide means which operate in unison with the oil burner pumps or the oil under pressure`delivered-Y tothe burnersA so that a uniform supply of air and fuel will be obtained at all times.

Another object of the invention is to provide an air flow regulator of the character described, which is actuated by variations in fluid pressure; for instance, by the oil or atomizing agent delivered to the burners or by variations in the boiler pressure.

Further objects will hereinafter appear. The invention consists of the parts and the construction, combination and arrangement of parts as hereinafter more fully described and claimed, having reference to the accompanying drawings, in which- Fig. 1 is a side elevation of a boiler, showin the application of the invention.

ig. 2 is an enlarged sectional detail vevv air admit ofthe mechanism 1whereby the dempers are actuated.

Fig. 8 is dicatcs in damper; ing damper r Mounted on the furr sliding damper is rocker arm on the damper 2 is a cranl: arm 6 and supported above the boiler is a shaft on which is secured a cranlr arm 8, said crank arrn being connected `with the rocher arm nd the crank arm 6 by means of links 9 an 10. Also secured on the shaft is cran arm 11 and connected with said arm is a. piston rod 12 which is actuated, as will herey inafter be described.

Mounted on one side of the hciler or at any convenient place adjacent t` e same is a steam actuated oil pump 1&1. Connected with said pump is a discharge pipe 15, which connects with a Supply line 16. ne end of this pipe delivers oil to the burner in the furnace while the opposite end of the pipe is connected with a1 cylinder 17. llounted on the pipe 15, between the pump and the supply pipe 16 is a pressure redncing valve 18 which in this instance is directly actuated by variations in the boiler steam pressure; that is, the -pressure-reducing valve shown' is of the diaphragm type,

one side of said diaphragm being directly o@ connected to the boiler by means of a pipe 19. This diaphragm actuates a. valve in the pipe line 15 and it can therefore be seen that variations in the boiler steam pressure will change the position of the valve in the pipe line 15, thereby varying the oil pressure in the supply line 16.

This variation of pressure in the supply line 16 is utilized to automatically operate the dampers 2 and 4, this being accomplished in the following manner: Referring to Fig. 2, 17 indicates a cylinder in which is slidably mounted a piston 20. This piston is secured to a piston rod 21 which extends through a stuhng box 22, the outer end of the rod 21 being pivotally attached as at 23, to a lever 24, which in turn is pivotally mounted as at 25, on a lever 26, said lever being' pivotally su ported at one end, as at 27, on a standar" 28 While the lid@ lill@ opposite end is attached to the piston rod 12 previously referred to; that is, the outer end of the lever 26 is fork-shaped to straddle the rod 12 and is also slotted, as at 29, to permit arcual movement of the lever 26 when reciprocal movement is imparted to the rodv 12. The piston rod 12 passes through a stuffing box 3() and is secured to a piston 31 which is reciprocally mounted in a cylinder 32.

Mounted on one side of the cylinder or formed integral therewith is a housing 33 in which is slidably mounted a piston valve 34. Formed in the housing 33 is a supply passage 35 and a second pair of passages 36 and 37, the passage 36 communicating with the upper end of the cylinder 32 and .the pasage 37 with the lower end of the cylinder.

The valve 34 serves the function of opening and closing the passages 36 and 37 and it is in this instanceconnected with the lever 24 by means of a rod 38. Mounted interior of the cylinder 17 and interposed between the piston 20 and the stuffing box 22 is a helical spring 40, the tension of which may be increased or decreased by means of the screws A41. Forming a connection between the cylinder 17 and the chamber 35 in the'housing 33 is a pipe 42, and connected with the opposite side of the cylinder 17 is the supply line pipe 16.

The operation of this lportion of the apparatus will be as follows: stated, variations in boiler steam pressure actuates the diaphragm valve 1 8 and thereby changes the flow and pressure of the oil discharging through the supply line 16. One end of this line is directly connected with the cylinder 17, as shown in Fig. 2, and it can therefore be seen that oil under pressure will be admitted to the lower end of the cylinder and that if the pressure is sulicient, upward movement will be transmitted to the piston 20 and the rod 21 secured thereto. Oil will simultaneously pass through the cylinder 17 and pipe 42 and will therefore enter the chamber 35. Upward movement of the rod 21 will transmit a rocking movement to the lever 24 about the pivotal connection 25, thereby transmitting an upward movement to the rod 38 and the piston valve 34 connected -therewith. Upward movement of the valve will open the passage 37 and close the passage 36, thereby permitting oil under pressure to enter the passage 37 and the lower end of the cylinder 32. The oil under p ressure thus admitted will 31 and the rod 12 attached thereto and the rocking movement will therefore be transmitted to thecrank arm 11 and the shaft 7, which in turn will be transmitted to the dampers 2 and 4 by means of the links 9 and 10.

As previously i elevate the piston Decrease in boiler pressure causes the valve 18 to move to a position where it will increase the pressure in the supply line 16. Increase of pressure in the supply line will raise the pistons 2() and 31, thereby opening the damp'- ers as an increased quantity of fuel is discharged through tlie burners. Increase in boiler pressure will actuate the valve 18 so that a decrease in pressure will take place in the supply line 16. Decrease in pressure will permit the piston 20 to move in a downward direction and as this movement is transmitted through the rod 21 to lower the lever 24, it can readily be seen that the piston valve 34 will reverse its position, thereby admitting oil under pressure to the upper end of the cylinder 32 and simultaneous y permitting exhaust of the oil contained in the lower end of .the cylinder'. The operation of the cooperating cylinders 17 and 32, by which fore automatic and as the action of the'4 spring 40 mounted in the cylinder 17 is exceedingly sensitive, it can readily be seen that slight variations in pressure in the supply line 16 will instantly efectthe supply oi discharge of oil from the cylinder 32.

The cooperation of the levers 24 and 26 is such that the larger lever will out-travel the other, thereby moving the piston valve 34 to a neutral position when the rod 12 and piston 31 attached thereto, moves a slight distance, whether in an upward or downward direction.. In fact, the movement of the rod 12, whether upwardly or downwardly, is intermittent to the extent that it may make a succession of-steps in an upward direction or in the reverse direction. It should, under ordinary working conditions, never travel a complete stroke of the cylinder.

From the foregoing description it can be seen that I have provided a fluid actuated mechanism which is exceedingly sensitive in action` therefore rendering it possible to maintain a fixed ratio of fuel oil and air undervarying conditions. It can further be seen that practically any amount of power desired for the work in hand may be provided by merely increasing or decreasing the diameter of the cylinder 32. If oil is delivered to the cylinder under a pressure of sixty pounds to the square inch and the diameter of the cylinder is five inches, then an area of approximately twenty square inches is provided and as the oil pressure specified is approximately sixty pounds, it can be seen that I obtain a working pressure equal to twenty times sixty or approximately twelve hundred pounds. Again, by referring to Fig. 2, it will be seen that the oil employed for the purpose of raising or lowering the piston 31 is not wasted as it is returned to the suction side of the pump by means of the pipe 50 whenever valve 34 moves to eX- haust or discharge position.

While the cylinders 17 and 32 are here shown as actuated by the fuel oil employed,

Alwish it understood that it may be directly actuated by steam delivered from the boiler orotherwise. Similarly, that while a more or less specic design is here shown, various changes in construction and proportions may be resorted to within the scope of the appended claims.

Having thus described my invention, what l claim and desire to secure by Letters Patcally mounted member to impart movement thereto, and means for transmitting said movement to open and close the damper. l 2. The combination with a boiler and furl nace, of an oil burner for the furnace, means for delivering oil under pressure to the burner, a damper adapted to regulate the air flow through the furnace, a cylinder,a piston reciprocally mounted in the cylinder, a

piston rod extending through the cylinder,

' secured to the piston, a valve actuated by pressure variations in the oil, adapted to admit oil to one side or another of the piston to raise and lower the same, and means for ltransmitting the movement of the piston in the rod to open 'and close the damper.

3. The combination with a boiler andfurnace, of an oil burner for the Jfurnace, means for delivering oil under pressure to the burner, a damper adapted to regulate the air flow through the furnace, a cylinder, means for by-passing a portion of the oil under pressure to said cylinder, a piston in the cylinder adapted to rise and fall with variations in oil pressure, a second cylinder, a piston Vreciprocally mounted in said cylinder, a valve in said cylinder adapted to be moved by the first-named piston, said valve adapted to admit oil under pressure to one end or another of the second named cylinder to raise or lower the piston mounted therein, and means for transmitting the movement of the piston in said cylinder to open and close the damper.

4. The combination with a boiler and furnace, of an oil burner for the furnace,

v `means for delivering oil under pressure to the burner, a damper adapted to regulate the air iiowthrough the furnace, a cylinder,

means for by-passing a portion of the oill under pressure to said cylinder, a piston in .the cylinder adapted to rise and fall vwith variations in oil pressure, a second cylinder, a piston reclprocall mounted in said cylinder, a valve .in sai cylinder adapted to bemoved by the first-named piston, said valve adapted to admit oil: under pressure to one end or another of the second named cylinder to raise or lower the piston mounted therein, means for transmitting the movement of the piston in said cylinder to open and close the damper, a spring engageable with the piston in the rst named cylinder,

and means for increasing or decreasing the tension of said spring.

5. 'The combination with a boiler and furnace, of an oil burner for the furnace, means for delivering oil under pressure to the burner, a damper adapted to regulate the air flow through the furnace, a cylinder, a pipe adapted to deliver a portion of the oil under pressure to said cylinder, a piston adapted .to be raised and lowered in the cylinder by variations in the oil pressure, a spring engageable with one end of the piston, means for increasing or 'decreasing the tension ofsaid spring, a piston rod secured to the piston and extending through the cylinder, a pivotally mounted lever to which the opposite end of the rod is sey cured, a second cylinder, a piston reciprocally mounted in said cylinder, a pivotally mounted lever adapted to be raised and lowered by said piston rod, said last named lever serving as a support for the first named lever, a valve in the second named cylinder adapted to be raised and lowered by the iirst named lever, a pipe connected with said valve adapted to deliver oil under pressure from the burner supply, said` valve adapted to direct the oil under pressure to one end or another of the second named cylinder to raise and to lower the piston, and means for transmitting the movement of the piston to open and close the damper.

6. The combination with a boiler and furnace, of an oil burner for the furnace, means for delivering oil under pressure to the burner, a damper adapted to regulate the air flowl through the furnace, a cylinder, a piston in said cylinder, a rod se# cured to the piston extending through the cylinder, means actuated by said rod for opening and closing the damper, means connecting the cylinder with the burner oil supply, a valve in the cylinder adapted to direct the oil to one end or another of the cylinder, to raise or to lower the piston mounted therein, and means actuated by changes in oil pressurefor moving the valve to automatically direct the oil to one end or another of the cylinder.

7. The combination with a boiler and furnace, of an oil burner for the furnace, means for delivering oil under pressure to the burner, a damper adapted to regulate the air flow through the furnace, a cylinder, a piston in said cylinder, a rod secured to the piston extending through the cylinder, means actuated by said rod for opere ing and closing the damper7 means connectthe valve toA neutral position when the pising the cylinder With the burner oil supton has moved in either direction.

ply, a Valve in the cylinder adapted to In testimony whereof I have hereunto direct the oil to one end or another of the Set my hand in the presence of two sub- 5 cylinder, to raise or to lower the piston scribing Witnesses.

mounted therein, means actuated by changes in oil pressure for moving the valve to auto- (/ARLYLE J SHERWOOD' matically direct the oil to one end or an- Vitnesses: other of the cylinder, and means actuated WM. H. BAUER,

10 by the movement of the piston for moving J. H. HERRING. 

